A Total Overhaul on the Lunaix's Virtual Memory Model (#26)

[lunaix-os.git] / lunaix-os / arch / i386 / mm / vmutils.c

diff --git a/lunaix-os/arch/i386/mm/vmutils.c b/lunaix-os/arch/i386/mm/vmutils.c
new file mode 100644 (file)
index 0000000..d7a98ea
--- /dev/null
+++ b/lunaix-os/arch/i386/mm/vmutils.c
@@ -0,0 +1,23 @@
+#include <lunaix/mm/vmm.h>
+#include <lunaix/mm/pmm.h>
+#include <sys/mm/mm_defs.h>
+
+ptr_t
+vmm_dup_page(ptr_t pa)
+{
+    ptr_t new_ppg = pmm_alloc_page(0);
+    mount_page(PG_MOUNT_3, new_ppg);
+    mount_page(PG_MOUNT_4, pa);
+
+    asm volatile("movl %1, %%edi\n"
+                 "movl %2, %%esi\n"
+                 "rep movsl\n" ::"c"(1024),
+                 "r"(PG_MOUNT_3),
+                 "r"(PG_MOUNT_4)
+                 : "memory", "%edi", "%esi");
+
+    unmount_page(PG_MOUNT_3);
+    unmount_page(PG_MOUNT_4);
+
+    return new_ppg;
+}
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